The present invention relates to motor vehicles, and more particularly to a drive system for automatically operating a door thereof.
Over the three-quarters of a century during which the automobile has been present, it has undergone a constant evolutionary process. Automobiles have been the subject of experimentation and invention by mechanics, engineers and scientists and no aspect of the system has escaped attention. Despite this fact, and despite the implementation of spring-loaded hinges, counterbalances and the like the operation of the doors on a modern-day motor vehicle continues to be difficult. As automobiles have grown larger and heavier, the size of their doors has increased to match. The manipulation of doors on larger automobiles has become a difficult task for children, and for aged or infirm individuals. While in many instances it is not overly difficult to open or close an automobile door while the vehicle is on a level plane should the vehicle be laterally inclined, as when parked on a hill or a steeply-crowned street, manipulation of the doors becomes excessively burdensome. This is due to the fact that when on a level plane one has only to overcome the inertia of the door; while on an incline one must actually raise the door against the force of gravity. Such a situation presents hazards, inasmuch as if the door is suddenly released it will forcibly shut, possibly injuring an individual's fingers or hand; and further, it presents a genuine problem for aged or infirm persons who are hard put to manage the heavy weight involved.
Attempts have been made to devise systems which would automatically open and/or close vehicle doors. Some examples of attempts are shown in U.S. Pat. Nos. 2,321,286--Etsel, 3,002,581--Deibel et al., and 2,628,091--Rappl. Electrically or electromechanically-operated systems have also been tried; examples of such systems may be found in U.S. Pat. Nos. 1,151,479--Kurtz and 3,069,151--Cook et al.
While a great deal of effort has obviously been expended in order to provide an automatic door opening system which is feasible for an automobile, to date it is well known that none of these effects have succeeded. Aside from a few specially-built automobiles having doors hinged in the roof structure and which swing upwardly, no automobiles are available which have automatic door opening systems. Thus, although the need is apparent and many have attempted to fulfill it, to date no system has been provided which is sufficiently safe, foolproof and economical to warrant its implementation in a mass-produced automobile. One reason for this is the fact that with most prior art systems a failure of the system would either cause the door to become stuck in an open position or conversely to remain closed, thus trapping the occupants of the vehicle until repairs could be accomplished. Still another problem is the elaborate nature of the prior art systems, which was detrimental to the reliability of such systems and made them quite difficult to install and maintain. Accordingly, it will be appreciated that it would be highly desirable to provide an improved door opening and/or closing system which obviates the foregoing disadvantages and is susceptible for installation in a mass-produced motor vehicle.
It is therefore an object of the present invention to provide an improved door opening mechanism.
Another object is to provide an automatic door mechanism which exhibits fail-safe operation.
Yet another object is to provide a physically compact door opening system susceptible of installation in present-day automobiles.
A further object of the present invention is to provide a door operating mechanism for a motor vehicle which is structurally simple and rugged.